Fuse.



FUSE.

APPLI CATIQN. HLED FLOV. 23, I916.

Patented Sept. 3, 1918.

iguana wow its-d s LOUI$ W. DOWNES, 0F PROVIDENCE, RHODE ISLAND.

FUSE.

Specification of Letters Patent.

Patented Application filed November 23, 1916. Serial No. 132,950.

To all whom it may concern.-

Be it known that I, LOUIS 'W. Downns, a citizen of the United States, and resident of the city of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improve ments in Fuses, of which the following is a specification.

This invention relates to electric indicating fuses more particularly to those of the cartridge type usually in very small sizes for use in circuits of low potential. Fuses of this type have usually heretofore had tubular bodies of glass and are "very delicate and easily broken in handling.

'The primary object of my present invention is to provide an indicating fuse of this diminutive size that is strong and durable and capable of withstanding the ordinary,

useto which such fuses are usually sub- *jlcctedfto accomplish which I have formed the, same with a comparatively solid body portion of wood, or other fibrous or non-' yielding material having a small longitu dinal fuse link carrying hole therethrough,

and have provided end caps for this body to which the link is connected. This body is alsoprovided with a transverse sight hole, the ends of which are covered with a transparent material through which the condition of the link may be readily observed.

' I With these and other objects in view, the

invention consists of certain novel features of construction, as will be more fullydescribed, and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1' is a central sectional elevation of my improved type of fuse.

'Fig. 2 is a perspective view showing the solid body portion of the fuse.

Fig 3-- is a central sectional end view through the body portion.

Fig.'4 is a perspective view of a transparent tubular-shaped closure for the ends of the sight hole.

Fi 5- is a cross section of the body showing the ends of the sight hole as closed by a transparent disk secured in position by the pasting of a label over its edges.

Fig. 6 is a section of the body showing a thin transparent sheet as wound about the body in spiral form to close the ends of the sight hole.

Fig. 7- is a view of one form of label which may be arranged to retain the closure vided with a sight hole 13 of greater diameter than the fuse link'hole which cuts through the body portion so as to intersect the small hole substantially midway the length of the body portion. The ends oi this body portion 10 are provided with corn *5 tact caps 14 of brass or other suitable con ducting material, which caps are attached to the body portion by pins 15, rivets, screws, indentations or by being crimped thereon or by other suitable means.

The ends of this sight hole 13 may be closed by any suitable transparent member 'or members, such for instance as the trans" parent tubular section 33 shown in Fig. 4, or the small disks 17 illustrated in Fig. which may be inserted. into countcr bored ends of the sight hole 13 as illustrated, or the-hole may be closed by a thin transparent sheet 18 shown in Fig. 6. which may be wound in spiral form about the body of the fuse over the ends of the sight hole. All of these closures serve the useful purpose preventing molten metal, sparks or flame from being thrown out through the sighthole when the lin k is blown.

When the disks 1? are employed for elos ing the sight hole, they may be retained in position by pasting labels over their edges, or by winding a label 20, see Fig. I, about the body portion of the fuse, which will be provided with holes 21 at the closures little smaller in diameter than that of the closing disks, so that the edges of the closing disks will be retained in their countersunk openings and yet permit unobstructed sight through the sight hole These tubes, disks or spiral sheets are n preferably constructed of gelatin rendered insoluble in water from an admixture of formaldehyde, or these closures may be con structed of other transparent insulating material not readily destroyed by flame.

I. ll ti "cult r That portion of the body which is visible through the transparentclosures may be stained; dyed or otherwise colored to render its appmirance attractive: The inner surface of the transparent hole may be colored white if desired so that the. condition of the fusible link may be more easily distinguished and the observer can tell whether or not the link has been blown. This particular type of fuse is more especially designed for use on circuits of low potential, and of relatively small amperage such for instance as the electric lighting systems, ignition systems and starting motor systems for automobiles and the like, and other circuits of very low capacity.

These systems are usually operated on from (3 to volts and, as a rule, the battery which forms the source of energy is capable of delivering approximately but 100 to 500 amperes even when short cirouited.

The chief advantages of my improved fuse are: first, it visually indicates the condition of the fuse link; second, it possesses great mechanical strength for a fuse of its very small size; and third, when this fuse 1S made in the preferred form with the insoluble gelatin closure for the sight hole,

.it becomes almost proof against breakage or mechanical injury in ordinary handling.

It has been found in practice thatwhen the automobile operator wishes to remove one of these small fuses from its clips or fuse block, he almost in ariably uses a screw driver as a. lever with which lo pry it loose. such rough treatment of the usual form of glass fuse frequently breaks and destroys it, then again when this old form of indicating fuse is used which has its indicating wire at or near the surface. this indicator is quite likely to be destroyed by such rough usage, and therefore. to ob *ialcthis dilli- I have provided an indicating fuse .wizh a comparatively solid body which has no readily injured parts, whereby this fuse is pus ssed of sullicienl strength to withstand considerable usage without injury.

it. will be readily seen that my improved fuse possessesall of the visually indicating advantages ofthe so-called glass fuse and exposed wire indicating fuse, and in addition has great injury resisting strength notpossessed by any other fuse which is due to the fact that the body portion of my fuse is solid and covered with a transparent material which is semi-flexible, resilient and not easily broken. which cmistruction enables it to withstand much mechanical abuse before it becomes injured to such an extent that it. will not continue to perform its normal function.

I have described one illustrative cmhodi ment of my invention. but the details of this construction may be varied without departing from the spirit of my invention. the scope of which is defined and limited only by the appended claims.

I claim:

1. An electric fuse comprising a body portion of iibrous material having a comparatively small lon 'illulinal bore lhcrellirouggh. end caps of conducting material tilled over said body and closing the ends of said bore. a fusible link extending through said here and connected lo said caps. the diameter of said bore being a little larger than that of said link, said body being provided with a transverse sight holc lherethrough, and a. transparent closure for lhe ends of said sight hole.

An electric fuse comprising a body por tion of tough non-yielding nultcrial having a comparativcly small hollow longiludiiuil bore thcrethrough. caps of conducting material on the ends of said body closing the ends of said bore. a fusible link extendin through said bore and connected to said caps. the diameter of said bore being a little greater than that of said link, said body bein; provided with a transverse sight hole, a closure of semi-flexible transparent material litted to cover the ends of said sight hole, and means for securing said closure in position.

In testimony whereof I allix my signature in presence of two witnesses.

LOUIS W. DOWNES.

lVitnesses: Grouse W'.. S'rnnnn,

P. O. BAKER. 

